“The NRSC is on track to spend over $5 million in Indiana and Arizona, which are two states that many had hoped [Republicans] would not have to spend money in,” the official said.

The NRSC has also stayed out of other potentially competitive Senate races, such as the Ohio and Florida contests.

The official criticized the Akin campaign for not releasing any polling data to prove it is competitive in Missouri.

“At a minimum, if the numbers were good, that would have boosted their fundraising several weeks ago,” the official said.

With polls showing McCaskill holding onto a single-digit lead, however, some observers have said the groups’ continuing refusal to get involved amounts to cutting off their nose to spite their face.

“Unless Akin gets completely crushed, they’ll look bad either way: if he wins, it shows that candidates can win by running against them; if he loses narrowly, they might have let their stubborn pride get in the way of taking back the Senate,” said Jeff Smith, a former Democratic state senator from Missouri.

“The only way they could possibly look good is by winning the Senate back without winning Missouri, and they have to pull an inside straight for that to happen,” Smith said.

Smith said he was “not totally convinced that NRSC or Crossroads wouldn’t come back in during the last few weeks,” calling their insistence on staying out “just a pride thing now.”

Walsh, the NRSC communications director, would not comment on any hypothetical scenario.

“We don’t broadcast our spending strategy to the Democrats, but we’re closely monitoring the race, as we do with every Senate race,” he said.

The Akin campaign has not yet released its third quarter fundraising numbers. Two weeks ago, McCaskill announced a $5.8 million haul. The Akin campaign’s silence suggests that their numbers are nowhere near that high.

A cash infusion from the NRSC or Crossroads could help make up for the likely deficit.

Crossroads began running ads in Missouri attacking McCaskill as early as 2011, long before she had a Republican opponent, and both Crossroads and the NRSC had reserved airtime for the general election.

“I think that anybody who’s been watching TV in Missouri over the past 18 months knows that Crossroads and the NRSC have spent a lot of time and money trying to stop Claire McCaskill,” said McCaskill spokesperson Caitlin Legacki.

Tyler estimated that groups pulling their funding had taken “anywhere from $5 million to $9 million” out of the race.

“We’ve held out own without their help,” he insisted, “and no one thought we’d be where we are.”